Protective measures for the Eckernförde Bay

In the period between April 2021 and March 2022, the project "Reallabor Eckernförder Bucht 2030", funded by the German Federal Foundation for the Environment (DBU) and led by the Center for Ocean and Society at the Christian-Albrechts-Universität zu Kiel (CAU), established an intensive dialog between research groups and various social stakeholders around the Eckernförder Bucht. Using the scientific and practical approach of a living lab, various proposed solutions were developed to improve the ecological condition of the Baltic Sea in the region. Fishermen, farmers, tourism experts and providers of water sports activities have all contributed, as have experts from the navy, campsite operators and environmental protection associations.

Possible measures now under consideration include the cultivation of bladder wrack and the restoration of rocky reefs, as well as other measures to retain nutrients naturally. This could bring the Baltic Sea in the Eckernförde region closer to a good environmental status in accordance with the requirements of the EU Marine Strategy Framework Directive. "Our goal was to identify measures that would find broad social consensus and take into account as many needs as possible," says project leader Dr. Christian Wagner-Ahlfs, who is responsible for stakeholder dialogue at the Center for Ocean and Society (CeOS) of the Kiel Marine Science (KMS) research center at Kiel University.

Bladderwrack to remove nutrients from the sea

The excessive input of nutrients primarily from adjacent agriculture into the Baltic Sea and the pollution already present in the Baltic Sea from previous inputs remain a key problem, affecting the growth of seagrass beds, for example. Among other things, nutrients promote the growth of planktonic and filamentous algae. These algae cloud the water and damage bottom-dwelling macroalgae and seagrass due to the lack of light. Finally, oxygen depletion may occur more frequently and fish kills may increase in the summer. "This is where we need to start anew and decisively improve water quality," emphasizes Professor Martin Wahl, benthic ecologist at GEOMAR Helmholtz Centre for Ocean Research Kiel. "First, of course, the nutrient input from agriculture must be further reduced. However, since many nutrients have already been deposited in the sediment on the seafloor, further measures make sense," explains Martin Wahl. The "Reallabor Eckernförder Bucht 2030" project has shown that bladder wrack can bind nutrients from the Baltic Sea. "We therefore want to examine where bladderwrack can be cultivated on a larger scale and how recycling on land could be organized to remove nitrogen from the water," says Wahl, the algae expert.

Shallow stone reefs: habitat for fish and algae

Another measure is the restoration of stone reefs. Until the 1970s, large stones such as granite boulders were deliberately removed from the sea as part of commercial stone fishing. As natural reef structures, these stone fields were important habitats for various species of fish, shellfish and algae, and also acted as coastal protection. "Stone fishing also destroyed an important natural substrate for bladderwrack," says Dr. Friederike Prowe of BioConsult GmbH & Co. KG, who is working on marine habitats as part of the project. Bladderwrack can bind larger amounts of nitrogen from Baltic Sea water and thus contribute to better water quality. "By restoring shallow reefs, we can not only create new habitat for bladderwrack. Bladder wrack also forms an important shelter for young fish. This also benefits fishermen and anglers in the medium term," Prowe said.

Near-natural coastal protection as an answer to the consequences of climate change

Coastal protection also plays an important role in the one-year pilot project. Above all, the coastal sections in the Eckernförde Bay that will be most affected in the coming years have been identified. "Climate change is likely to present us campsite owners with major challenges," predicts Philipp Hoff, who runs a campsite directly on the beach in Karlsminde. "Flood events and storm surges could occur more frequently, damaging our infrastructure. We therefore want to focus on nature-compatible solutions and can only benefit from the findings in the project."

Participants in the project "Reallabor Eckernförder Bucht 2030" are Kiel University with the Center for Ocean and Society, the Institute of Geography, the Institute of Geosciences and the Institute of Crop Science and Plant Breeding, GEOMAR Helmholtz Centre for Ocean Research Kiel, the Fraunhofer Institute for Computer Graphics Research (IGD, Rostock), the companies BioConsult GmbH & Co. KG and Coastal Research and Management GbR (CRM), the Schleswig-Holstein State Office for Agriculture, Environment and Rural Areas (LLUR), and the Schleswig-Holstein Ministry for Energy Transition, Agriculture, Environment, Nature and Digitalization (MELUND). More than 50 stakeholders were involved via video conferences, face-to-face meetings and working meetings.

Related links:

www.reallabor-eckernfoerde.de